Automatic screw machine



Sept-5,1944; H. w. RUPPEL I 2,357,428

AUTOMATlC SCREW MACHINE Filed M 11, 1940 7 Sheets-Sheet 1 INVENTOR. rg/ Wappe/ ATTORNEYS 7 Sept. 5, R P 2,357,428

AUTOMATIC SCREW MACHiNE Filed May 11, 1940 -7 Sheets-Sheet. 2'

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H. W. RUPPEL AUTOMATIC SCREW MACHINE Filed May 11 1940 invswnom;

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S p 1944" H. w. RUPPEL AUTOMATIC SCREW MACHINE 7 Sheets-Sheet 4 Filed -May 11, 1940 INVENTOR.

Q/Wg Wapoq/ ATTORNEY;

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AUTOMATIC SCREW MAcnmE Filed May 1;, 1940 '7 Shets-Sheet 5 i b i fiP/argg Q/QM P a; w'wa ww p 194 4 H. w. RUPPEL 2,357,428

I AUTOMATIC SCREW MACHINE Filed'May 11, 1940 7 Sheets-Sheet 6 641-10 uays I H. w. .RUPPEL 1 2,357,428 AUTOMATIC .VYSCREWI'MACHINE Filed May 11; 1940 7 shaets sh et w ys Patented Sept. 5, 1944 UNITED STATES PATENT OFFICE AUTOMATIC SCREW MACHINEv Harry W. Ituppel, Cleveland, Ohio, assigncr to The Foote-Burt Company, Cleveland, Ohio, a

corporation of Ohio Application May 11,1940, Serial No. 334,627

' driving .thespindle 13, this transmission being 17 Claims.

The present invention relates to automatic screw machines, and hasparticular reference to a hydraulic-transmission for driving or controlling the various operating elements of such machines.

One of the objects of the present invention is to provide a novel hydraulic transmission which is operable either automatically or manually to obtain a program of speeds including rapid traverse and a wide range of selective feeds.

A more specific objectis to providea new and improved hydraulic transmission for an automatic screwmachinehaving a multiple tooi turret axially reciprocable in a cutting stroke and periodically rotatable. to index successive tools into operative position, said transmission being adjustable to provide independentfeed rates for the different tools in their respective operating cycles.

. Other objects and advantages will become apparent as'the description proceeds.

In the accompanying drawings, Figure 1 is a front perspective View of a machine having a hydraulic transmission embodying the features of my invention.

Fig. 2 is a diagrammatic representation of-the movable elements of the machine- Fig. 3 is a diagrammatic representationof the hydraulic transmission.

Fig. 4 is a fragmentary'transversepartial vertical sectional-view of the machine.

Fig. 5 is a sectional view taken substantially along line 55 of Fig. 4.

-Figs.--6 and '7 are transverse sectional views taken respectively along lines 6-6 and 1-'l of Fig.5. I

Fig. 815 a sectional view of a valve forming part of the transmission system.

Fig. 9 is a longitudinal sectional view of another valve.

Figs. 10 to 14, inclusive, arev transverselsectional views taken respectively along lines ll)l ll to l4-l4 of Fig. 9.

Figs. and iii are detail sectional views respectively of two other Valves.

Fig. 17is a fragmentary detail view of ally-- draulic motor-forming part of the transmission. Referring .moreparticularlyto the drawings, the automatic screw machine constituting the exemplary embodiment of the invention comprises a hollow elongatedhorizontal frame It) .rigidly mounted on afloor base I l. One end of the irame l -0is formed integral withan elevated housing 12 enclosing a rotatably supported hollow work spindle [3. A gear'transn ission'is provided for connectedthrough pulleys I4. andl5 and connecting belts I6 to a main drive shaft .Il driven by a motor I8. The transmission includes a reversing vmechanism l9 operable bya hydraulic actuator 20, a high and low speed mechanism 2| operable by a hydraulic actuator 22 and speed change gearing 23 as more fully disclosed in my copen ding application Serial No. 334,623, filed May ll, 1940. Thehydraulic actuators 2D and,

22 are respectively under the control of two valves 24and .25 operable automatically in predetermined timed. relation by. a cam disk 26 driven by a cam shaft 21 extending longitudinally through the frame Ill.

' Abar of stock W is adapted tobe fed intermittently through the spindle l3 .and between the jaws ofanautomatic chuck 28 by a stock feed mechanism-'29. The chuck-28 and the-stock feed mechanism29 are automatically. operable in timed sequence by a cam drum-30 on the shaft 21. The construction of the chuck 28.and the stock feed mechanism, is more fully disclosedin my copending application.Serial No..3'34,626, filed May 11, 1940, .now'Patent No.- 2,310,259, dated February 9, 1943.

The otherend of the frame I01 is formed with elevated horizontal guides 31' supporting a slide 32 for adjustment longitudinally of the spindle l3. A tool turret 33 havinga plurality-of annularly arranged parallel tool receivinglholes 34, is mounted in a turret housing 35- integral with the slide 32 for axial reciprocation and for rotation to bring successive tools (not-shown) into operation upon the bar stockprojecting axially from the chuck 28. The reciprocatory drive for the turret 33 comprises a cam drum 36having a on the underside of the slide 32. A pluralityof cam rollers 38 corresponding in number and spac-- ing to the holes 34 project'radially from the-turret 33 for selective engagement with thegroove 31. The cam drum 36 is adapted to be rotated through the internal gear 39 meshingwi th the pinion 49 ona sleeve 4| receiving the camshaft 21. An intermittent-Geneva motion device Q42 is operable by a roller 43 on-one. end of the cam drum 36 to index the-turret-33 through a distance between consecutiv toolholes 34 each time-"that the turret is retractedinto inoperative position. The turret indexing mechanism is more-fully disclosed in my copending application Serial No. 334, 25. filed'-May 1l,-1940. I

Two cross slides 44 and 45are mounted on the front andrear of theframe [0 between the spindle l3 and the turret 33, and are adapted to support additional tools (not shown) for operating on the stock bar. An automatically operable independent cut-off mechanism 46 is mounted on the spindle housing l2 for severing the finished work piece from the stock bar at the end of the machine operation. The cross slides 44 and 45 and the cut-off mechanism 46 are operable from the main cam shaft 2! of the machine.

The two drive shafts 21 and 4| are adapted to be driven in timed relation by a rotary hydraulic motor 41. This motor has a shaft 48 connected through a worm 49 and worm wheel 50 to a shaft in turn connected through a worm 52 and worm wheel 53 to the sleeve 4!. The shaft 5| is connected through reduction gears 54 to a shaft 55 in turn connected through a worm 56 and worm wheel 51 to the cam shaft 21. The speed ratios are such that the cam drum 36 will rotate the required number of times, for example, six times, to index the various holes 34 of the turret 33 successively into a working station relative to the work while the cam shaft 21 is making one complete revolution.

The rotary hydraulic motor 41 may be of any suitable construction adapted to operate at rapid traverse and variable feed rates. It is mounted on a base plate 58 within the machine frame l0, and connected to a high pressure inlet or supply passage 59 and an exhaust passage 60. Full details of the internal construction of the motor 41 are not shown since, per se, they constitute no part of the invention. A fragment of one of the piston and cylinder units of the motor 41 is, however, disclosed in Fig. 17, and will be hereinafter described to facilitate a clearer understanding of the control of the hydraulic transmission. It is suificient to say at this time that the motor is of the piston type, having a plurality of large pistons adapted to be rendered inactive upon a predetermined rise in back pressure, and a plurality of small pistons active at all times, either without the large pistons to handle the entire volume of motive fluid supplied to effect rapid traverse operation, or conjointly with the large pistons to effect feed operation. The motor 41 is therefore adjustable to operate at either rapid traverse or feed on any given volume of motive fluid supplied through the conduit 59. The rate of feed operation is further subject to variation by altering the volume of motive fluid supplied. In the present instance, the motor 41 has a feed change of from 3 to 240 R. P. M., and a rapid traverse rate of approximately 2000 R. P. M.

A variable delivery pump 6| having a suction or intake passage 62 opening from a sump 63 within the frame I0, is connected to deliver a fluid medium, such as oil, under a relatively high pressure to the conduit 59 leading to the motor 41.. The-pump BI is adapted to be driven at a constant speed from a suitable source of power, such as-the electric motor [8. Thus, the pump 6| has a drive shaft 64 connected through gears 65 and 66 to the line shaft H. An adjustable relief valve 61, discharging to the sump 63, is connected in a branch of the pressure passage 59, and limits thepressure of the motive fluid displaced by the pump 6i to a predetermined maximum. The exhaust passage 6|] of the motor 41 discharges to the sump 63 and has a back pressure valve 68 interposed therein.

Regulation of the effective back pressure to adjust the volumetric capacity of the motor is under'the control of a valve 69. Fig. 17 shows one cylinder of the motor 41 open at the pressure end to a passage H which is adapted for reciprocable axially within the cylinder 70.

'the cylinder 10 and is slidably mounted on the small piston 16 for relative movement into and out of abutting engagement with the shoulder 15. Opening to the low pressure end of the cylinder 10 is a control passage 18. The contiguous end of the large piston 11 is formed with a peripheral notch 19 so that the control passage 18 will be open to the cylinder 10 in all positions of reciprocation of the two pistons.

The valve 69 is operable to connect the control passage 18 either to the exhaust passage 60 at the outlet side of the back pressure valve 68 or to a low pressure passage 80 adapted to receive fluid under a fluctuating pressure from the pump 6|. In its preferred form, the valve 69 comprises a casing 8| which is formed with a valve bore 82 and with two peripheral ports 83 and 34 in the bore connected respectively to the passages 60 and 18. A valve member 85 of the spool type is reciprocable in the bore 82. One end of the bore 82 constitutes a fluid pressure cylinder connected to the passage 80, and the contiguous end of the valve member 85 constitutes a fluid pressure responsive piston formed with a peripheral port 86 in free communication with the passage 86 and movable into and out of communication with the port 84. A coiled compression spring 81 engages the other end of the valve member 85 and normally acts to maintain the valve member in one end position wherein the ports 83 and 84 are in communication and the port 86 is blocked. In

this position of the valve, no back pressure is maintained in the motor cylinder 16, and consequently the large piston 11 will remain in engagement with the shoulder 15 and will reciprocate as a unit with the small piston 16 to effect feed operation.

When the pressure in the passage 80 is increased to a point suflicient to overcome the pressure of the spring 81, the valve member 85 will be shifted to interrupt communication between the ports 83 and 84 and to establish communication between the ports 84 and 86. As a result, fluid will be supplied through the passage 18 to establish a back pressure in the cylinder l0, and this back pressure will maintain the large piston 1! against the pressure end of the cylinder 10 so that the entire volume of the motive fluid supplied through the passage 59 will be handled by the small piston 76 to effect rapid traverse operation.

The pressure of the fluid within the low pressure passage 80 is caused to fluctuate selectively to above and below the minimum pressure required to actuate the control valve 69 in op po;

sition to the spring 81. This pressure variation is under the control of a charging and neutral valve. 88 (see Fig. 16) which is connected to open and close a by-pass from the low pressure passage to the sump 63. In its preferred form, the valve 88 comprises a housing 89 having a valve bore 90 formed with an annular port 9| opening to a drain passage 92 leading to the sump 63. One end of the bore 99 is enlarged to define a chamber 93 connected to an-inlet passage 94 from the pump 6| and to the low pressure-passage 89. The other end of the bore 99 is connected: to a control passage 95 adapted to be selectively opened and closed as hereinafter described. A valve plunger 96 is reciprocable in the bore 99, and is normally urged inwardly by a coiled compression spring 91 into position to block the port 9| from the chamber 93, this position being defined by a stop pin 98. The valve plunger 96 is formed with a restricted bleed hole or opening 99; opening therethrough to permit a comparatively gradual equalization of pressures in opposite ends of the valve bore 99. In operation, when the control passage 95 is blockedfor closed, fluid from the chamber 93 passes through the small hole 99 to equalize the pressures acting on opposite ends of the valve plunger 96. As a result, the spring 91 maintains the plunger, 96 in the innermost position against the stop pin 98 to block the port 9|. The pressure in the low pressure passage 89 is therefore elevated sufficiently to effect actuation of the control valve 69 for rapid traverse motor operation. When the control passage 95 is opened, the pressure back of the valve plunger 96 is partially dissipated, and hence a hydraulic differential acting in opposition to the spring 91 is established. It will be understood that the flow of fluid through the hole 99 is sufficiently restricted to maintain this differential. As a result, the valve plunger 96 is moved to partially open position into a state of equilibrium to spill or by-pass excess fluid from the low pressure passage 89 to the sump 63. The attendant pressure drop in the passage 89 permits the control valve 69 to condition the motor 41 for slow feed operation.

The control conduit 95. is subject to be selectively blocked or opened either by an automatic valve I99 (Fig. 15) operable from the cam shaft 21 to obtain a predetermined program of rapid transverse and feed movements in the automatic machine cycle, or by a hand operable valve I9I (Figs. 9 to 14) available at any time to assume control. IllIis of the rotary type, having an actuating lever I92 at the front of the machine frame I9. The valve I9I comprises a suitable casing I93 formed with a longitudinal bore I94, and closed at the ends by suitable plates I95 and I96. A valve sleeve I91 is fixed in the bore I94, and a rotary valve member or plug I98 is mounted therein and has axial end extensions I99 and H9 projecting through the end plates I95 and I96. A pinion III is fixedon the extension I99, and meshes with a gear sector II2 operable by the hand lever I92.

The valve bore I94 is formed with longitudinally spaced inner peripheral grooves H3, H4, H5, H6, H1 and H8 which open respectively through ports II9, I29, I2I, I22, I23 and I24 to the interior of the sleeve .I91. Formed in the valve member I98 are a plurality of transverse bores or passages I25, I26, I21, I28 and I29 and two diametrically spaced longitudinal grooves I39'opening from the bore I25. These bores and grooves are disposed for movement into and outof communication with the ports I29 to I24 and H9 respectively. The bores I25 to I29 are in intericommuni cation through an axial bore I3 I formed in the valve member I98 and opening throughthe axial extension II9.' A pressure relief valve is interposed in the axial bore I3I fluid to the bores I28 and I29 when the relief In the present instance, the hand valve I valve is open.

The various grooves II3 to II5 are connected respectively to a branch I36 of the mainpressure passage 59, an auxiliary pressure passage I31 and the control passage 95. An exhaust or drain passage I38 opens from the groove H5 and also from the groove II1 through a longitudinal groove I39 connecting the grooves IE5 and H1. The groove H8 is connected to a control passage I49 which is an extension of the passage and which leads to the automatic valve I99. The valve plug I98 has four selective positions of rotary adjustment which are identified by the legends Rapid, Feed, Stop and Automatic affixed to the front of the machine frame I9 in association with the hand lever I92. In the stop position as shown in Figs. 9 to 14, all of the passages are connected to drain. More specifically, the motive fluid normally passing from the pump-6I through the passage 59 to the motor 91 is released or by-passed to the sump 63 through I36-II3--Il9-I39-I25-I3I-I21- I22-I I9-I38 to stopthe operation of the motor. Similarly, the passages I31 and 95 are connected respectively through the grooves H4 and H5, the ports I29 and I2I and the bores I25 and E28 to the axial bore NH, and thence in common through the bore I21, the ports I22 and the groove M6 to the exhaust passage I38. In the other three valve positions, the grooves I39 are out of communication with the ports l I9 to block the branch pressure passage I39, the bore I25 is out of communication with the ports I29 to block the pressure passage I31, and the bore I21 is out of communication Wlth'the ports I22 to disconnect the axial bore I3I from the drain passage I39, so that the system is conditioned for operation. In the automatic position, the exhaust ports I23 are blocked, and the control passages 95 and 549 are connected, thereby placing the motor l'i under the control of the automatic valve. The ccnnectionis from 95, through II5 I2II26-I3I-re1ief valve I32, I33-I29I24- II8 to I49. When the valve I9I is adjusted out of the automatic position, the ports I24 are blocked to interrupt the connection and thereby functionally disable the automatic valve I99. hi the rapid position, the ports I2I are blocked to disconnect the control passage 95 from the exhaust passage I38. In the feed position, the control passage 95' is connected through II5 I I1-I-39I I6 to the drain passage I38. The re-' lief valve I32, I33 is set to maintain a minimum pressure in the control passage 95, both in the feed position and the automatic position of the valve I91, so as'to insure the maintenance of a correspondingly reduced pressure in the low pressure passage 89 for operating various ma-.

sure in the low pressure passage 80 is only slightly higher than the pressure in the control passage 95 by the amount of pressure required to overcome the pressure of the spring 91 in opening the valve 88.

The automatic valve I (Fig. 15) comprises a casing I4I mounted within the frame l0, and having port connections with the control passage I40 and a drain passage I42 leading to the sump 63. Mounted within the casing I4I are two projecting valve plungers I43 and I44 which are mechanically interconnected by a link I45 for alternate actuation respectively to disconnect and connect the passages I40 and I42. More particularly, the plunger I43 when moved inwardly serves to block or close the control passage I40, and to project the plunger I44 outwardly into position for external actuation, and hence is termed the rapid traverse plunger. Similarly, the plunger I44 when moved inwardly serves to project the plunger I43 outwardly into position for external actuation, and thereby to effect connection of the passages I40 and I42, and hence is termed the feed plunger. The plungers I43 and I44 are arranged for automatic operation respectively by rapid traverse and feed dogs I46 and I41 on a cam disk I48 fixed on the main camshaft 21. In the present instance, the disk I 48 is formed with two concentric series of peripherally spaced arcuate slots I49 and I50 in which the dogs I46 and I41 are respectively secured. Six slots are provided in each series, and hence any number of associated dogs, from one to six in each set, may be provided and relatively adjusted on the disk, the number and spacing of the dogs of the two sets being dependent on the desired program of movements in each machine cycle. It will be seen that the disk I48 will make one complete revolution for each complete revolution of the turret 33. By virtue of this arrangement, six sets of two or more dogs I46 and I41, one for each tool hole 34, may be provided so that the program of rapid traverse and feed movements for each of the series of tool reciprocations in the complete machine cycle may be independently controlled, Similar independent control of the speed and direction of rotation of the spindle I3 for each tool reciprocation is also afforded by the disk 26 with an appropriate number of dogs for actuating the valves 24 and 25.

The pump 6| is of the variable delivery type. Details of the pump construction are not shown since, per se, they form no part of the present invention. It is sufficient to say that the pump 6i embodies means having an external control shaft I SI for adjusting the displacement from zero 01' neutral to maximum. Variations in the fluid displacement of the pump 6| into the passage 59 will result in corresponding changes in the speed of the motor 41.

Means is provided for automatically controlling the pump displacement particularly effec. tive during feed operation to adjust the speed of the motor 41 as desired over a given range, whereby each of the tools may be translated at an independent rate when in feed in the course of its cutting cycle. In the present instance, this means comprises a feed regulator mechanism I52 (Figs. 4, and 6) having a casing I53 mounted in an opening I54 in the front of the machine frame I0. Journaled in the casing I53 and projecting from the lower end thereof is a vertical shaft I55. An arm I56 fixed on the lower end of the shaft I55 is connected through an adjustable link I51 to an arm I58 fixed 0n the pump control shaft I5I. A coiled tension spring I59 anchored at opposite ends to the frame I0 and the arm I56 tends to rotate the shaft I5I in a direction to adjust the pump 6| toward neutral, 1. e., to reduce the pump displacement. A series of hydraulic actuators I60 are arranged along the shaft I55 within the casing I53, and are selec tively operable to rotate the shaft in opposition to the spring I59 into a predetermined feed position.

The hydraulic actuators I60 are alike in construction, and hence a description of one will suifice for all. Referring to Fig. 5, the actuator (III the port under pressure will be I60 comprises a single end cylinder I6I formed in the casing I53. A piston I62 is reciprocable in and projects from the cylinder I6I for movement transversely of the shaft I55. The outer end of the piston I62 is formed in one side with a notch I63 presenting a transverse abutment face I64 in engagement with a lateral arm I65 fixed on the shaft I55. Upon the supply of pressure fluid to the closed end of the cylinder I6I the piston I62 will be moved outwardly to rotate the shaft I55 in a direction to increase the displacement of the pump 6|. Outward movement of the piston I62 is limited by a micrometer stop screw I66 mounted in the casing I53 for adjustment from the front exterior of the machine frame I0 to obtain the desired rate of tool feed. In the present instance, the inner end of the screw I 66 extends into th casing I53 for end engagement by the piston I62. It will be understood that there is a shaft arm I65 and a stop screw I 66 to determine the feed adjustment for each of the actuators I60. Six actuators are provided to correspond in number to the turret holes 34, and to provide an independent feed rate control for each tool.

Selectiv operation of the hydraulic actuators I60 in accordance with the successive index positions of the tool turret 33 is under the control of a rotary selector valve I61. This valve has a cylindrical casing I68 on the rear of the casing I53 and formed with six peripherally spaced ports I 69 connected respectively through passages or lines I10 to the pressure ends of the cylinders I6I. The casing I68 is also provided with diametrically spaced pressure and exhaust ports HI and I12 connected respectively to the low pressure and drain passages and 60. A rotary valve member I13 is mounted in the bore of the casing I 68, and is connected to the cam shaft 21 through gears I14 and H5 for continuous indexin rotation in timed relation to the indexing movements of the turret 33. The valve member I13 I16 always in communication with the exhaust passage 60 and partially interrupted by a land I11 movable individually across the ports I69. The member I13 is also formed with a passage I18 which opens at one end to a peripheral groove I19 always in communication with the low pressure passage 80. Two charging ports I80 and I8I open at longitudinally paced points from the passage I18 to the face of the land I11. One port I80 is in the transverse plane of three of the ports I69 (Fig. 7) and the other port I8I is in the transverse plane of the other three ports I69 (Fig. 6). It will be seen that in each rotation of the valve member I15, during which the turret 33 will be indexed step-bY-step through one revolution, fluid under pressure will be supplied individually to the successive actuator ports I69, and those ports in the train of connected to is formed with a peripheral recess.

:operable Valve 10!,

I lthedrain passagetu; ,Itfollows that whileeach tool=is;in the working stationand' moving through its -,cu-tting 'cycle,, the-associated one of the actuators I60 is rendered operative to determine the available rate of feed movement. Each feed &rate may be adjusted over a substantial range,

and the independent feed rates for. any two or .zmore of the tools may bemade'alike or different, :by appropriate individual adjustments of ,thestopscrews I66, ,toobtain the feed rate best adapted for, eachtype of metal removing oper-- ation.,

The hydraulic system lso-includes-the actuaztors =20 wand 22 for the direction and speed :clutches in the drive for the work spindle 'I-3.

Thus, the "control valves 24 :and 25Hfor these actuators are-connected in common to the drain passage I38. .The valve 24 .is connected tothe ,pressure passage 131 which branches fromthe passage 60 .at the up-stream' side of the back :pressure valveBB, and thevalve 25 is connected "to :a branch of the low pressure passage 80.

In operation, referring particularly to Fig. 3,

the line :80, the valve =69 is operable to connect the'jlin'es 18 .and'80 so {8.8130 adjust the displacement of the motor 41 forwrapid-traverse.

.Upon a drop .in pressure :in the .line 80, the valve' 69 isoperable to connect-th controlline18 to the drain :line .60 so as to .adjust'fthe displacement of "the-,motor 741 for feedrope'ration. Hence, the .motor ll is adjustable in response .to pressure fluctuationsinthe auxiliary pressure line 80 and these pressure fluctuationsare' effected by the valve 88 under control of theline '95, intturn controlled by the "valve "I or "the valve llll. The speed of the motor 4''! is also subject to variation by adjusting the-displacement of the pumpBI through the medium of the unit I52.

I claim as my invention: 7

1. In a machine tool, in combination, a support, a turret havingaplurality of peripherally spaced fixture supporting I means and being .-mounted on saidsupportfor recurrent reciprocation and for rotary-indexing movements between successive reciprocations,meansincluding a hydraulic motor for reciprocating andindexing said turret in. timed relation, a variable delivery pump having an adjustment member and connected to supply :fluid under pressure to said motor,-and means-automatically operable in timed relation to the indexing movements of said turret to :control said adjustment member, said last-men- .tioned means including a plurality of hydraulic actuators for said adjustment member selectively .operablein successivepositions of said turret and individually adjustable to vary the extent of movement of saidmember.

:2. In a machine tool, in combination, a support, a movable element mounted on said support for recurrentlreciprocation, means including a-hydraulic motor for reciprocating said element, a variable deliverypump having a displacement adjustment =member and connected to supply fluid under-pressure to said motor to operate the latter at a speed corresponding to the pumpdisplacement, agplurality of hydraulic actuators individuallysoperable tor-adjust said memben means Upon a rise in pressure in -for individually determining theextent of move- .ment of saidactuators-and thereby the adjustment of said member, and valve means operable in timed relation to said element to effect successive operation of said actuators.

3. In a machine tool, in combination, a support, a machine element mounted for movement on said support, means including a hydraulic motor for drivingsaid element, said motor being adjustable to vary its displacement for obtaining 7 rapid traverse'and feed operation, a pump having a discharge passage connected to supply motive fluid to said motor,.an auxiliary fluid pressure passage, means including a control passage operable' when blocked to effect a pressure rise in said auxiliary passage and when unblocked to effect a 1 pressure reduction insaid auxiliary passage, hy-

draulic means controlled by said auxiliary passage to effect adjustmentof said motor for a rapidtraverse operation in response to said pressure rise and feed-operation in response to said pressure drop, and means operable selectively to block and unblock saidcontrol passage.

4. In a machine tool, in combination, a support, a machine'element mounted for movement on said support, means including :a hydraulic motor for driving said element and being adjustablein-displacement to obtain rapid traverse and feed rates, a pump having a discharge passage connected to supply motive fluid to said motor and having an: auxiliary discharge-passage, a drain, means including a control passage operable when blocked from said drain to effect a 7 pressure rise in said auxiliarypassage andwhen unblocked to-effect-apressure reduction in said auxiliary passage, hydraulic meanscontrolled by said auxiliary passage to effect adjustment of said motor fora rapid traverse operation in response to said pressure rise and feed operation in response to said pressure drop,yand means automatically operable in timed relation to the movement of said element to alternately block and unblock saidcontrol passage.

5. Ina machine tool, in combination,-a sup-.

port, a machine element mountedfor movement on said support, means including a hydraulic motor for driving said element: and being adjustablein displacement to obtain rapid traverse and feed rates, apump havinga discharge passage connected to supply motive fluid to said motor and having an auxiliary discharge passage, a drain, a valve for by-passing said auxiliary passage to said drain and having a valve member with one end exposed to the pressure in said auxiliary passage and the other end connected through a bleed portto'said auxiliary passage,

spring means tending to urge said valve member into closed position, a control passage opening from. said other end of said valve member, a low pressure relief valve interposed in said control passage, valve means operable in one position to connect said control passage to drain whereby to vhydraulically unbalance said .valve member to cffoot opening of said valve, and in another position to disconnect said control passage from drain whereby to efiect hydraulic balance of said valve member through said port and consequent closing of said valve, and means controlledby said auxil- -iary passage to adjust said motor for rapid traverse operation when said valve is closed and feed operation when said valve is open. 7

6. In a machine tool, in combination, a support, a machine element mounted for movement on 1 said support, means including a hydraulic motor ior driving said element, said said drain.

motor being adjustable to vary its displacement for obtaining rapid traverse and feed operation, a pump having a discharge passage connectedto supply motive fluid to said motor, an auxiliary fluid pressure passage, means including a control passage operabl when blocked to effect a pressure rise in said auxiliary passage and when I unblocked to eiTect a pressure reduction in said auxiliary passage, hydraulic means controlled by said auxiliary passage to eifect adjustment of said motor for a rapid traverse operation in response to said pressure rise and feed operation in response to said pressure drop, a valve operable alternately to block and unblock said control passage, a disk rotatable by said motor, and dogs adjustably mounted on said disk for actuating said valve in predetermined timed relation to the movement of said element.

7. In a machine tool, in combination, a support, a machine element mounted for movement on said support, means including a hydraulic motor for driving said element, said motor being adjustable to vary its displacement for obtaining rapid traverse and feed operation, a pump having a discharge passage connected to supply motive fluid to said motor, an auxiliary fluid pressure passage, means including a control pas sage operable when blocked to effect a pressure rise in said auxiliary passage and when unblocked to effect a pressure reduction in said auxiliary passage, hydraulic means controlled by said auxiliary passage to effect adjustment of said motor for a rapid traverse operation in response to said pressure rise and feed operation in response to said pressure drop, a drain, and a valve operable in one position to connect said control passage to said drain and in another position to disconnect said control passage from 8. In a machine tool, in combination, a support, a machine element mounted for movement on said support, means including a hydraulic motor for driving said element, said motor being adjustable to vary its displacement for obtaining rapid traverse and feed operation, a pump having a discharge passage connected to supply motive fluid to said motor, an-auxiliary fluid pressure passage, means including a control passage operable when blocked to effect a pressure 'rise in said auxiliary passage and when unblocked to efiect a pressure reduction in said auxiliary passage, hydraulic means controlled by said auxiliary passage to efifect adjustment of said motor fora rapid traverse operation in response to said pressure rise and feed operation in response to said pressure drop, a relatively unrestricted drain passage, 2. second drain passage including a low pressure relief valve, and a valve operable selectively to connect said control passage to said unrestricted drain passage, or said second drain passage or to disconnect said control passage from said drain passages.

9. In a machine tool, in combination, a support, a machine element mounted for movement on said support, means including a hydraulic motor for driving said element, said motor being adjustable to vary its displacement for obtaining rapid traverse and feed operation, a pump having a discharge passage connected to supply motive fluid to said motor, an auxiliary fluid pressure passage, means including a control passage operable when blocked to effect a pressure rise in said auxiliary passage and when unblocked to effect a pressure reduction in said auxiliary passage, hydraulic means controlled by said auxiliary passage to effect adjustment of said motor for a rapid traverse operation in response to said pressure rise and feed operation in response to said pressure drop, a second control passage, a

' valve means automatically operable in timed relation to said element for alternately opening and closing said second control passage;

10. In a machine tool, in combination, a movable element, means including a hydraulic motor for driving said element, a pump having a high pressure discharge passage connected to said motor, an exhaust passage opening from said motor and including a back pressure valve, a drain and a manual control valve selectively operable in one position to block said high pressure passage and said exhaust passage from said drain and in another position to connect said high pressure passage and said exhaust passage in advance of said back pressure valve to said drain.

11. In a machine tool, in combination, a movableelement, means including a hydraulic motor for driving said element, a pump having a first discharge passage connected to said motor and having a second discharge passage, an exhaust passage opening from said motor and including a back pressure valve, a drain, means including a control passage operable to eifect a pressure rise in said second passage when said control passage is closed and to effect a pressure drop in said second passage'when said control passage is connected to said drain, and a control valve selectively operable in one position to block said first passage, said exhaust passage and said control passage from drain, and in another position to connect said first passage, said exh ust passage, and said control passage to drain.

12. In a machine tool, in combination, a support, a spindle mounted for rotation on said support and having a chuck, a stock feed mechanism for advancing bar stock periodically through said spindle into said chuck, means for driving said spindle including direction control clutch means having a hydraulic actuator and including selective speed control clutch means having a hydraulic actuator, a tool element mounted on said support for movement relative to said chuck, means including a hydraulic motor for driving said stock feed mechanism and said tool element, a pump having a main discharge passage connected to supply motive fluid to said motor and having a second discharge passage, an exhaust passage including a back pressure valve opening from said motor, means for controlling the pressure in said second passage and including a control passage effective when blocked from exhaust to cause a pressure increase in said second passage and when connected to exhaust to efiect a pressure reduction in said second passage, hydraulic means for adjusting the speed of said motor in response to pressure variations in said second passage, valve means operable to connect said second passage alternately to opposite sides of the hydraulic actuator for said speed control clutch, valve means for connecting said exhaust passage ahead of said back pressure valve alternately to opposite sides of the hydraulic actuator for said direction control clutch, means operable in timed relation to said motor to actuate said two valve means in timed sequence, and valve means manually operable at willfor controlling said main passage and said control and exhaust passages, said valve means having a stop position connecting said last mentioned passages to drain, a feed position blocking said main passage and said exhaust passage from drain and connecting said control passage to drain, and a rapid traverse position blocking said main passage, exhaust passage and control passage from drain.

13. In a machine tool, in combination, a support, a spindle mounted for rotation on said support, means for driving said spindle including control clutch means having a hydraulic actuator, a tool element mounted on said suppOrt for movement relative to said spindle, means including a hydraulic motor for driving said tool element, a pump having a main discharge passage connected to supply motive fluid to said motor and having a second discharge passage, meansfor controlling the pressure in said second passage and including a control passage effective when blocked from exhaust to cause a pressure increase in said second passage and when connected to exhaust to effect a pressure reduction in said second passage, hydraulic means -for adjusting the speed of said motor in response to pressure variations in said second passage, valve means operable to connect said second passage alternately to opposite sides of said hydraulic actuator, and valve means for controlling said main and control passages, said valve means having a stop position connecting said last mentioned passages to drain, a feed position blocking said main passage and connecting said control passage through a low pressure relief valve to drain, and a rapid traverse position blocking said main passage and control passage from drain.

14,-. In a machine tool, in combination, a support, a spindle mounted for rotation on said support, means for driving said spindle including direction control clutch means having a hydraulic actuator and including selective speed control clutch means having a hydraulic actuator, a tool element mounted on said support for movement relative to said chuck, means including a hydraulic motor for driving said tool element, a pump having a main discharge passage connected to supply motive fluid to said motor and having a second dischargepassage, an exhaust passage including a back pressure valve opening from said motor, valve means operable to connect said second passage alternately to opposite sides of one of said hydraulic actuators, valve means for connecting said exhaust passage alternately to opposite sides of the other of said hydraulic actuators, and means operable in timed relation to said motor to actuate said two valve means in timed sequence.

15. In a machine tool, in combination, a support, an element movable on said support, a hydraulic transmission for driving said element and including speed adjusting means having a control passage adapted when blocked to effect one rate of travel and when unblocked to effect a different rate of travel, a second control passage, a valve operable to connect and disconnect said passages, and a valve automatically operable in.

predetermined adjustable timed relation to the movement of said element selectively to block and unblock said second control passage.

16. In a machine tool, in combination, a support, an element movable on said support, an exhaust passage, a hydraulic transmission for driving said element and including speed adjusting means having a control passage adapted when connected to said exhaust passage to establish one rate of travel of said element and when disconnected from said exhaust passage to establish a different rate of travel of said element and also including speed adjusting means having an adjustable member for selectively adjusting the slower rate of travel of said element, valve means for selectively connecting and disconnecting said passages, and means automatically operable in timed relation to the movements of said element to adjust said member to obtain a predetermined sequence of slow rate movements.

17. In a machine tool, in combination, a support, a turret having a plurality of peripherally spaced fixture supporting means and being mounted on said support for recurrent axialreciprocation and for rotary indexing movements respectively between successive reciprocations to position said fixture supporting means successively in a working station, hydraulic means for reciprocating and indexing said turret and having means including a control unit for effecting selective rapid traverse and feed movement-s, a cam disk continuously rotatable by said hydraulic means in timed relation to the rotation of said turret, and a plurality of sets of dogs adjustably mounted on said cam disk for actuating said control unit independently for different index positions of said turret whereby to obtain independent programs of rapid traverse and feed movements respectively for said turret in said difierent index positions.-

HARRY W. RUPPEL. 

